/******************************Copyright(C) Nubo*******************************
File name  : crc.c
Description: check crc method  0x18005 X16+X15+X2+1
Platform   : MDK V5.23.0.0
Version    : V1.0
Author     : 
Create Time: 2018-1-3
Modify     : 
Modify Time: 
******************************************************************************/

#include "cn_crc.h"

const uint16_t CRCTable[] =
{
    //多项式为    0x18005   X16+X15+X2+1
    0x0000,0xC0C1,0xC181,0x0140,0xC301,0x03C0,0x0280,0xC241,
    0xC601,0x06C0,0x0780,0xC741,0x0500,0xC5C1,0xC481,0x0440,
    0xCC01,0x0CC0,0x0D80,0xCD41,0x0F00,0xCFC1,0xCE81,0x0E40,
    0x0A00,0xCAC1,0xCB81,0x0B40,0xC901,0x09C0,0x0880,0xC841,
    0xD801,0x18C0,0x1980,0xD941,0x1B00,0xDBC1,0xDA81,0x1A40,
    0x1E00,0xDEC1,0xDF81,0x1F40,0xDD01,0x1DC0,0x1C80,0xDC41,
    0x1400,0xD4C1,0xD581,0x1540,0xD701,0x17C0,0x1680,0xD641,
    0xD201,0x12C0,0x1380,0xD341,0x1100,0xD1C1,0xD081,0x1040,
    0xF001,0x30C0,0x3180,0xF141,0x3300,0xF3C1,0xF281,0x3240,
    0x3600,0xF6C1,0xF781,0x3740,0xF501,0x35C0,0x3480,0xF441,
    0x3C00,0xFCC1,0xFD81,0x3D40,0xFF01,0x3FC0,0x3E80,0xFE41,
    0xFA01,0x3AC0,0x3B80,0xFB41,0x3900,0xF9C1,0xF881,0x3840,
    0x2800,0xE8C1,0xE981,0x2940,0xEB01,0x2BC0,0x2A80,0xEA41,
    0xEE01,0x2EC0,0x2F80,0xEF41,0x2D00,0xEDC1,0xEC81,0x2C40,
    0xE401,0x24C0,0x2580,0xE541,0x2700,0xE7C1,0xE681,0x2640,
    0x2200,0xE2C1,0xE381,0x2340,0xE101,0x21C0,0x2080,0xE041,
    0xA001,0x60C0,0x6180,0xA141,0x6300,0xA3C1,0xA281,0x6240,
    0x6600,0xA6C1,0xA781,0x6740,0xA501,0x65C0,0x6480,0xA441,
    0x6C00,0xACC1,0xAD81,0x6D40,0xAF01,0x6FC0,0x6E80,0xAE41,
    0xAA01,0x6AC0,0x6B80,0xAB41,0x6900,0xA9C1,0xA881,0x6840,
    0x7800,0xB8C1,0xB981,0x7940,0xBB01,0x7BC0,0x7A80,0xBA41,
    0xBE01,0x7EC0,0x7F80,0xBF41,0x7D00,0xBDC1,0xBC81,0x7C40,
    0xB401,0x74C0,0x7580,0xB541,0x7700,0xB7C1,0xB681,0x7640,
    0x7200,0xB2C1,0xB381,0x7340,0xB101,0x71C0,0x7080,0xB041,
    0x5000,0x90C1,0x9181,0x5140,0x9301,0x53C0,0x5280,0x9241,
    0x9601,0x56C0,0x5780,0x9741,0x5500,0x95C1,0x9481,0x5440,
    0x9C01,0x5CC0,0x5D80,0x9D41,0x5F00,0x9FC1,0x9E81,0x5E40,
    0x5A00,0x9AC1,0x9B81,0x5B40,0x9901,0x59C0,0x5880,0x9841,
    0x8801,0x48C0,0x4980,0x8941,0x4B00,0x8BC1,0x8A81,0x4A40,
    0x4E00,0x8EC1,0x8F81,0x4F40,0x8D01,0x4DC0,0x4C80,0x8C41,
    0x4400,0x84C1,0x8581,0x4540,0x8701,0x47C0,0x4680,0x8641,
    0x8201,0x42C0,0x4380,0x8341,0x4100,0x81C1,0x8081,0x4040
};

/*******************************************************************************
函 数 名：  ChkCrcValue
功能说明：  校验CRC，初值为0
参    数：  buf-待校验的数据
            len-长度
返 回 值：  INT16U-返回crc值
*******************************************************************************/
uint16_t ChkCrcValue(uint8_t *buf, uint16_t len)
{
#if 1
    uint16_t i;
    uint8_t  index;
    uint8_t  CRCH = 0;                      //以前是0xFF,由于上位机改成了0，此处改成0
    uint8_t  CRCL = 0;                      //以前是0xFF,由于上位机改成了0，此处改成0

    for( i = 0 ; i < len ; i++ )                            //传输消息缓冲区
    {
        index = CRCH ^ buf[i];
        CRCH  = (uint8_t)CRCL ^ (uint8_t)CRCTable[index];
        CRCL  = CRCTable[index] >> 8;
    }
    return( CRCH<<8|CRCL) ;     //CRCH 在数据流中先发送 CRCL 在数据流中后发送
#endif
#if 0
    uint16_t i;
    uint16_t cksum = 0;
    for (i = 0;  i < len;  i++) 
    {
        cksum = CRCTable[(cksum ^ *buf++) & 0xff] ^ (cksum >> 8);
    }
    return cksum; 
#endif
}
/*******************************************************************************
函 数 名：  ChkCrcValueEx
功能说明：  校验CRC，初值可以自带
参    数：  buf-待校验的数据
            len-长度
            FirstData-
返 回 值：  INT16U-返回crc值
*******************************************************************************/
uint16_t ChkCrcValueEx(uint8_t *buf, uint16_t len, uint16_t FirstData)
{
    uint16_t i;
    uint8_t  index;
    uint8_t  CRCH = 0;                      //以前是0xFF,由于上位机改成了0，此处改成0
    uint8_t  CRCL = 0;                      //以前是0xFF,由于上位机改成了0，此处改成0
    
    CRCH = (uint8_t)(FirstData>>8);
    CRCL = (uint8_t)(FirstData);
    
    for( i = 0 ; i < len ; i++ )                            //传输消息缓冲区
    {
        index = CRCH ^ buf[i];
        CRCH  = (uint8_t)CRCL ^ (uint8_t)CRCTable[index];
        CRCL  = CRCTable[index] >> 8;
    }
    return( CRCL<<8|CRCH) ;     //CRCH 在数据流中先发送 CRCL 在数据流中后发送
}

/*******************************************************************************
函 数 名：  ChkCrcValueEx
功能说明：  校验CRC，初值可以自带
参    数：  buf-待校验的数据
            len-长度
            FirstData-
返 回 值：  INT16U-返回crc值
*******************************************************************************/
uint16_t ChkCrcValueEx_Cut(uint8_t *buf,uint8_t *buf_Cut, uint16_t len, uint16_t Cut_len, uint16_t FirstData)
{
    uint16_t i;
    uint8_t  index;
    uint8_t  CRCH = 0;                      //以前是0xFF,由于上位机改成了0，此处改成0
    uint8_t  CRCL = 0;                      //以前是0xFF,由于上位机改成了0，此处改成0
    
    CRCH = (uint8_t)(FirstData>>8);
    CRCL = (uint8_t)(FirstData);  
    for( i = 0 ; i < Cut_len ; i++ )                            //传输消息缓冲区
    {
        index = CRCH ^ buf[i];
        CRCH  = (uint8_t)CRCL ^ (uint8_t)CRCTable[index];
        CRCL  = CRCTable[index] >> 8;
    }
	
    for( i = 0 ; i < (len - Cut_len) ; i++ )                            //传输消息缓冲区
    {
        index = CRCH ^ buf_Cut[i];
        CRCH  = (uint8_t)CRCL ^ (uint8_t)CRCTable[index];
        CRCL  = CRCTable[index] >> 8;
    }
    return( CRCL<<8|CRCH) ;     //CRCH 在数据流中先发送 CRCL 在数据流中后发送
}



/**************************Copyright Nubo 2018-01-03*************************/

